package zuoye15;

public class zuoye555 {
    public static void main(String[] args) {
        //        5：求1-20之间的数的乘积(double)
        double sum = 1;
        for (int i = 2; i <= 20; i++) {
            sum = sum * i;
        }
        System.out.println("1*2*3...*20=" + sum);
    }
}
